In order to practice acrylics, here is what you can do relatively inexpensively. Sacrifice one sketchbook to acrylic painting. If you do not have a sketchbook, get one for no more than $12, you choose the size, I recommend 9×12.
Purchase the sketchbook at the book store not the art store. For some reason, book stores have better, longer lasting sketchbooks that cost less than an art store. Another reason you would want an unlined journal is because it will serve as the best art reference book for years. You will know exactly what works and what does not work through experience, and have the proof on the pages.
Lay all of your acrylic paints onto your palette. About a nickel size in diameter is all you need at the moment. Just spritz water on them to keep the paint moist. Take a flat brush and plop one after another in a straight line into your notebook. Be sure to rinse the color out before starting a new color mix. There are no rules for your journal, you can paint across the entire length of the book, or just on one page. Acrylics are perfect for journals. Write down what you observe with each color. For example, “this yellow ochre is a bit thin and see-through.” Or develop a system. If you want to get really technical, dedicate one page to each of your paints to write down the properties, experiment and observe.
When you have learned about your color palette, it is time to mix them with one another. If you have a very large palette, this can be a tedious chore. Break it down to a small palette of three to five colors to start. Eventually, you will have mixed each one with each other.
It is easier to remember the actual pigment name rather than the acrylic tube name. In other words, It is easier to remember PB29 rather than Ultramarine Blue, and it is much easier to write it down in your sketchbook too. You see, the PB29 label is the actual pigment itself, this is across the board and each manufacturer will use it for that pigment. However, one manufacturers Ultramarine Blue is another’s Royal Blue, Emperor Blue and the like.